Mammals will evolve (to choose an analogy) but they do not revert to being reptiles. If the subjects of this research had simply disagreed about the exact biographical dates of the model this would not have been problematic. If research subjects, for example, had argued to extend the period of middle adulthood to fifty rather than forty-five, for example, as people work until they are older than had been the case when Levinson was working, this would have in general supported his findings.
The validity of his model is not dependent on being absolutely precise in his age-related break-points and while Levinson himself might not have acknowledged this, it makes sense that details of the different stages should have to be shifted to meet changes in society. Such an acknowledgement is in fact missing from Levinson's model (as well as from the models of Erikson and Piaget) and must be seen as a substantial weakness of these models. Levinson describes his model as being essentially independent of social and cultural constraints, as arising from individual and personal attributes and developmental issues. However, while individual experiences are of course always an essential aspect of how individuals make sense of their world, their social experiences and social identity are equally important. This is something that is ignored by Levinson's model, and something that would in all likelihood have been included had Levinson based his model on experimental data.
Dannefer's 1984 study on Levinson's model in fact focuses on precisely this point, arguing that Levinson's model is deeply flawed because it ignores the primacy of social relationships as powerful influences on an individual's development and sense of self.
Dannefer continued to do research in this area as he sought to reconcile Levinson's model with the lack of subjective concurrence with this model and the relationship between the fact that research subjects did not self-identify with the stages in Levinson's model with...
In a 1992 study, he summarized this problem with Levinson as follows:
Some theorists have proposed models in which social context is largely irrelevant. For example, although Levinson et al. (1978) pay lip service to the important influence of social context they describe stages and sequences of adult development that are universal across cultures and historical periods. They even assert that age timetables exist which do not vary across different contexts. As a result, context is in effect irrelevant and adult development stages are "not subject to environmental shaping except at the pathological extremes."
That social context matters only in pathological extremes seems to us to be highly unlikely from our current vantage point.
I began this critique of Levinson's model by noting that his model was very much a product of his time. It was an era in both academic psychology and a number of echelons in American culture in general in which social order was seen not as a social good but as a simple factual aspect of human nature and human society. This was, after all, the era of functionalist in which social structures were defined in essentially self-referential terms: Structures existed because they were functional, and their functionality could be derived from the fact that they existed.
Levinson's model of carefully parsed life stages in which individuals moved relatively smoothly (and without the need for any extensive self-analysis or grasping after insight) through all of the stages of their lives fits rather neatly into the idealized life span of the typical productive worker in the decades after World War II. Levinson seems to have looked around him, assessed from an external vantage point how people were running their lives, and derived a model that explained what he saw -- but more importantly derived from how he and the others with whom he was working believed that people should envision their lives.
